The invention relates to soil resistant, aqueous polish compositions comprising film-forming polymers and an ionic silicone surfactant.
This invention relates to polishing compositions, particularly floor polishes. The suitability of a polish applied to a substrate is often dependent on a variety of physical properties that are affected by the choice of surfactant. For example, the smoothness and the resistance to soiling of a polish can depend on the surfactant. xe2x80x9cSmoothnessxe2x80x9d refers to the uniformity of the coating after the surface applied polish has dried to form a film. xe2x80x9cResistance to soilingxe2x80x9d refers to the ability of the polish to retain its appearance after exposure to soil.
Surfactants reduce the surface tension of the polish and thereby improve the wetting and leveling characteristics of the polish. Fluorocarbon surfactants, dating back to the mid-1950s, have been the most popular wetting and leveling agents used by the floor polish industry. These surfactants, further described in U.S. Pat. Nos. 2,937,098 (Geen) and 3,163,547 (Vietor), are typically used at very low concentrations such as about 0.01% by weight of the total formulation. Because the fluorocarbon surfactants can be used at such low levels, they typically pose only minor adverse affects on the final properties such as the soil resistance of the dry polish film.
Many fluorocarbon surfactants contain perfluorooctyl moieties. These surfactants ultimately degrade to perfluorooctyl-containing compounds. It has been reported that certain perfluorooctyl-containing compounds can tend to bio-accumulate in living organisms; this tendency has been cited as a potential concern regarding some fluorochemical compounds. For example, see U.S. Pat. No. 5,688,844 (Baker et al.). As a result, there is a recognized need to replace the fluorocarbon surfactants in floor polishes.
Some non-fluorinated surfactants for floor finishes are known in the art. U.S. Pat. No. 3,728,418 (Gleason) discloses various phosphate compounds. U.S. Pat. Nos. 4,168,255 (Lewis et al.), 4,017,662 (Gehman et al.) and 3,554,790 (Gehman) disclose alkali metal and amine salts of fatty acids having 12 to 18 carbon atoms. U.S. Pat. No. 4,131,585 (Feigin) discusses the use of a non-linear aliphatic hydrocarbon or mixture of hydrocarbons containing 8 to 15 carbon atoms or an alkylbenzene moiety containing 8 to 12 carbon atoms in the alkyl chain as leveling agents.
The use of various nonionic wetting agents, prepared by the addition of ethylene oxide to compounds containing one or more active hydrogen atoms, are disclosed in U.S. Pat. No. 4,017,662 (Gehman et al.). U.S. Pat. No. 4,317,755 (Gregory) recites that nonionic surfactants are preferred, although anionic surfactants can sometimes be used in floor polishes. Preferred nonionic surfactants are the ethylene oxide and/or propylene oxide derivatives of alkyl phenols, aliphatic acids, aliphatic alcohols, glycols, glycol ethers, alkylaryl esters and vegetable oils. U.S. Pat. No. 4,923,514 (Brown) discloses floor polish formulations with surfactants such as nonyl phenol ethoxylates, alkoxylated amine, and ethoxylated fatty amines.
The use of a hydrolytically stable polysiloxane-oxyalkylene block copolymer having a molecular weight below about 25,000 is disclosed in U.S. Pat. Nos. 3,306,869 (Lahr et al.) and 3,429,842 (Wolstoncroft) as a leveling agent in a floor polish.
Most of these non-fluorinated leveling agents must be used at higher concentrations than the fluorinated materials in the floor polish formulations. Consequently, they are more likely to adversely affect important physical properties of the coating such as resistance to soiling. Some surfactants have such high molecular weights that they cannot effectively migrate to the surface of substrate and provide the desired surface tension reduction required for the production of smooth coatings. Moreover, the hydrocarbon surfactants typically do not produce coatings that are resistant to soiling, an important criteria for a polishing composition.
We have provided a surfactant that has minimal adverse affects on the final properties of the dried coating. Ionic silicone surfactants have good wetting and leveling characteristics that facilitate the production of a smooth coating while maintaining good anti-soiling properties. The ionic silicone surfactants perform comparably to state-of-the-art fluorochemical surfactant.
The present invention provides an aqueous polishing composition comprising an ionic silicone surfactant and a film-forming polymer. The polishing compositions can produce smooth and soil resistant coatings when applied to a substrate such as, for example, floor, wall, and bathroom surfaces. The polishes are particularly well suited for application to floor surfaces. The polish compositions perform as well as state-of-the art formulations containing a fluorocarbon surfactant.
Typically, the polishing composition contains from about 0.01 to about 5.0 weight percent ionic silicone surfactant based on the weight of the polishing composition. The ionic silicone surfactant comprises a silicone group and one or more ionic groups. In one preferred embodiment the ionic group is anionic. Suitable anionic groups include carboxylate, sulfonate, phosphonate, sulfate, phosphate, and the like. Preferably, the anionic group is a carboxylate. A particularly preferred carboxylate group is phthalate. A portion of the anionic groups can be an acidic moiety such as carboxylic acid, sulfonic acid, phosphonic acid, sulfuric acid, phosphoric acid, and the like. The average molecular weight of the surfactant is less than about 10,000.
The film forming polymers are typically acrylic polymers, acrylic copolymers, styrene-acrylic copolymers, or blends thereof. The floor polish compositions can also contain polyvalent metal compounds, alkali soluble resins, waxes, permanent and fugitive plasticizers, defoamers, and biocides.
The solids content of the polishes ranges from about 10 to about 50 weight percent based on the weight of the polish composition. The static surface tension typically ranges from about 18 to about 30 dynes/cm.
Another aspect of the invention provides methods of using the polishing compositions of the invention.